Moved to send instead of [], so no columns specifically required, only methods.

lib/paperclip.rb

@@ -182,7 +182,7 @@ module Paperclip
           options[:in] = (0..options[:less_than])
         end
         
-        if attachment.file? && !options[:in].include?(instance[:"#{name}_file_size"].to_i)
+        if attachment.file? && !options[:in].include?(attachment.instance_read(:file_size).to_i)
           min = options[:in].first
           max = options[:in].last
           
@@ -223,7 +223,7 @@ module Paperclip
         
         unless attachment.original_filename.blank?
           unless options[:content_type].blank?
-            content_type = instance[:"#{name}_content_type"]
+            content_type = attachment.instance_read(:content_type)
             unless valid_types.any?{|t| t === content_type }
               options[:message] || "is not one of the allowed file types."
             end

lib/paperclip/attachment.rb

@@ -56,7 +56,7 @@ module Paperclip
     def assign uploaded_file
       %w(file_name).each do |field|
         unless @instance.class.column_names.include?("#{name}_#{field}")
-          raise PaperclipError.new("#{self} model does not have required column '#{name}_#{field}'")
+          raise PaperclipError.new("#{@instance.class} model does not have required column '#{name}_#{field}'")
         end
       end
 
@@ -75,17 +75,17 @@ module Paperclip
 
       logger.info("[paperclip] Writing attributes for #{name}")
       @queued_for_write[:original]        = uploaded_file.to_tempfile
-      @instance[:"#{@name}_file_name"]    = uploaded_file.original_filename.strip.gsub /[^\w\d\.\-]+/, '_'
-      @instance[:"#{@name}_content_type"] = uploaded_file.content_type.strip
-      @instance[:"#{@name}_file_size"]    = uploaded_file.size.to_i
-      @instance[:"#{@name}_updated_at"]   = Time.now
+      instance_write(:file_name, uploaded_file.original_filename.strip.gsub(/[^\w\d\.\-]+/, '_'))
+      instance_write(:content_type, uploaded_file.content_type.strip)
+      instance_write(:file_size, uploaded_file.size.to_i)
+      instance_write(:updated_at, Time.now)
 
       @dirty = true
 
       post_process
  
       # Reset the file size if the original file was reprocessed.
-      @instance[:"#{@name}_file_size"]    = uploaded_file.size.to_i
+      instance_write(:file_size, uploaded_file.size.to_i)
     ensure
       validate
     end
@@ -148,11 +148,11 @@ module Paperclip
     # Returns the name of the file as originally assigned, and as lives in the
     # <attachment>_file_name attribute of the model.
     def original_filename
-      instance[:"#{name}_file_name"]
+      instance_read(:file_name)
     end
     
     def updated_at
-      time = instance[:"#{name}_updated_at"]
+      time = instance_read(:updated_at)
       time && time.to_i
     end
 
@@ -209,6 +209,14 @@ module Paperclip
       !original_filename.blank?
     end
 
+    def instance_write(attr, value)
+      instance.send(:"#{name}_#{attr}=", value)
+    end
+
+    def instance_read(attr)
+      instance.send(:"#{name}_#{attr}")
+    end
+
     private
 
     def logger
@@ -280,10 +288,10 @@ module Paperclip
       @queued_for_delete += [:original, *@styles.keys].uniq.map do |style|
         path(style) if exists?(style)
       end.compact
-      @instance[:"#{@name}_file_name"]    = nil
-      @instance[:"#{@name}_content_type"] = nil
-      @instance[:"#{@name}_file_size"]    = nil
-      @instance[:"#{@name}_updated_at"]   = nil
+      instance_write(:file_name, nil)
+      instance_write(:content_type, nil)
+      instance_write(:file_size, nil)
+      instance_write(:updated_at, nil)
     end
 
     def flush_errors #:nodoc:

test/attachment_test.rb

@@ -232,12 +232,12 @@ class AttachmentTest < Test::Unit::TestCase
     
     context "with a file assigned in the database" do
       setup do
-        @instance.stubs(:[]).with(:avatar_file_name).returns("5k.png")
-        @instance.stubs(:[]).with(:avatar_content_type).returns("image/png")
-        @instance.stubs(:[]).with(:avatar_file_size).returns(12345)
+        @attachment.stubs(:instance_read).with(:file_name).returns("5k.png")
+        @attachment.stubs(:instance_read).with(:content_type).returns("image/png")
+        @attachment.stubs(:instance_read).with(:file_size).returns(12345)
         now = Time.now
         Time.stubs(:now).returns(now)
-        @instance.stubs(:[]).with(:avatar_updated_at).returns(Time.now)
+        @attachment.stubs(:instance_read).with(:updated_at).returns(Time.now)
       end
 
       should "return a correct url even if the file does not exist" do
@@ -251,7 +251,7 @@ class AttachmentTest < Test::Unit::TestCase
 
       context "with the updated_at field removed" do
         setup do
-          @instance.stubs(:[]).with(:avatar_updated_at).returns(nil)
+          @attachment.stubs(:instance_read).with(:updated_at).returns(nil)
         end
 
         should "only return the url without the updated_at when sent #url" do
@@ -264,7 +264,7 @@ class AttachmentTest < Test::Unit::TestCase
       end
 
       should "return the proper path when filename has multiple .'s" do
-        @instance.stubs(:[]).with(:avatar_file_name).returns("5k.old.png")      
+        @attachment.stubs(:instance_read).with(:file_name).returns("5k.old.png")      
         assert_equal "./test/../tmp/avatars/dummies/original/#{@instance.id}/5k.old.png", @attachment.path
       end
 
@@ -331,10 +331,10 @@ class AttachmentTest < Test::Unit::TestCase
                 @existing_names = @attachment.styles.keys.collect do |style|
                   @attachment.path(style)
                 end
-                @instance.expects(:[]=).with(:avatar_file_name, nil)
-                @instance.expects(:[]=).with(:avatar_content_type, nil)
-                @instance.expects(:[]=).with(:avatar_file_size, nil)
-                @instance.expects(:[]=).with(:avatar_updated_at, nil)
+                @attachment.expects(:instance_write).with(:file_name, nil)
+                @attachment.expects(:instance_write).with(:content_type, nil)
+                @attachment.expects(:instance_write).with(:file_size, nil)
+                @attachment.expects(:instance_write).with(:updated_at, nil)
                 @attachment.assign nil
                 @attachment.save
               end